Three of the classic "founding fathers" of sociology (Comte, Marx and Tocqueville) were contemporary observers of the French Revolution of 1848. In addition, another important theoretical tradition was represented in contemporary observations of 1848 by Pierre-Joseph Proudhon. The present paper summarizes aspects of the views of these theoretically minded observers, notes some points at which more recent historical research suggests revisions to these classical views, and poses three arguments: (1) The revolution of 1848 exerted a direct shaping influence on classical social theory through lessons (some now subject to revision) learned from observation of the revolutionary struggles. (2) The 1848 revolution influenced classical social theory indirectly by contributing to the submergence of the radical French revolutionary tradition (along with utopian socialism) after the defeat of the June insurrectionaires and Bonaparte's coup. (3) Both writers in the classical tradition and current researchers have failed to thematize adequately a basic transformation in effectiveness of national integration, communication and administration which made 1848 in crucial ways much more akin to 1789 than it was direct evidence for the growth of class struggle and the likelihood of further revolution in advanced capitalist countries